International Myeloma Working Group molecular classification of multiple myeloma: spotlight review

Molecular characteristics of mantle cell lymphoma presenting with clonal plasma cell component

The normal counterparts of mantle cell lymphoma (MCL) are naive, quiescent B cells that have not been processed through the germinal center (GC). For this reason, although lymphomas arising from GC or post-GC B cells often exhibit plasmacytic differentiation, MCL rarely presents with plasmacytic features. Seven cases of MCL with a monotypic plasma cell (PC) population were collected from 6 centers and were studied by immunohistochemistry, fluorescence immunophenotyping and interphase cytogenetics as a tool for the investigation of neoplasms analysis, capillary gel electrophoresis, and restriction fragment length polymorphism of immunoglobulin heavy chain analysis of microdissections of each of the MCL and PC populations to assess their clonal relationship. The clinical presentation was rather unusual compared with typical MCL, with 2 cases arising from the extranodal soft tissues of the head. All MCL cases were morphologically and immunohistochemically typical, bearing the t(11;14)(q13;q32). In all cases, the PC population was clonal. In 5 of the 7 cases, the MCL and PC clones showed identical restriction fragments, indicating a common clonal origin of the neoplastic population. The 2 cases with clonal diversity denoted the coexistence of 2 different tumors in a composite lymphoma/PC neoplasm. Our findings suggest that MCL can present with a PC component that is often clonally related to the lymphoma, representing a rare but unique biological variant of this tumor.

Primary plasma cell leukemia: a retrospective multicenter study of 73 patients

BACKGROUND

Epidemiological and clinical information on primary plasma cell leukemia (pPCL) are rarely reported. The aims are to evaluate the clinical features, prognostic factors, and efficacy of treatments in pPCL.

PATIENTS AND METHODS

A multicenter retrospective cohort study was carried out from January 2000 to December 2008 in 26 Italian hematology divisions. A total of 128 cases of plasma cell leukemia were collected, and 73 of them (57%) were classified as primary (male/female 43/30).

RESULTS

Sixty-four patients had at least 1 sign of end-organ damage and 10 had extramedullary localization. One patient died early; of the remaining patients, 36 (50%) received anthracycline-based regimens as first-line therapy, 17 (24%) single alkylating agents, and 30 (42%) bortezomib or thalidomide as additional (n = 11) or unique treatments (n = 19). Twenty-three patients (31%) underwent autologous and/or allogeneic hematopoietic stem cell transplantation (HSCT). The median overall survival (OS) was 12.6 months; complete or partial response was achieved in 22 (30%) and 18 patients (25%), respectively; the median duration of response (DOR) was 16.4 months. HSCT patients had a longer OS and DOR (median 38.1 and 25.8 months, respectively) compared with nontransplanted patients (9.1 and 7.3 months, respectively, P < 0.001). OS was influenced by nonresponse to treatment, hypoalbuminemia, and HSCT. DOR was favorably influenced only by HSCT.

CONCLUSIONS

pPCL is an aggressive disease with a poor prognosis and a low response rate to conventional therapy. HSCT is effective, increasing OS and DOR by 69% and 88%, respectively. The use of bortezomib and thalidomide may improve outcomes.

Complete response correlates with long-term progression-free and overall survival in elderly myeloma treated with novel agents: analysis of 1175 patients

Complete response (CR) was an uncommon event in elderly myeloma patients until novel agents were combined with standard oral melphalan-prednisone. This analysis assesses the impact of treatment response on progression-free survival (PFS) and overall survival (OS). We retrospectively analyzed 1175 newly diagnosed myeloma patients, enrolled in 3 multicenter trials, treated with melphalan-prednisone alone (n = 332), melphalan-prednisone-thalidomide (n = 332), melphalan-prednisone-bortezomib (n = 257), or melphalan-prednisone-bortezomib-thalidomide (n = 254). After a median follow-up of 29 months, the 3-year PFS and OS were 67% and 27% (hazard ratio = 0.16; P < .001), and 91% and 70% (hazard ratio = 0.15; P < .001) in patients who obtained CR and in those who achieved very good partial response, respectively. Similar results were observed in patients older than 75 years. Multivariate analysis confirmed that the achievement of CR was an independent predictor of longer PFS and OS, regardless of age, International Staging System stage, and treatment. These findings highlight a significant association between the achievement of CR and long-term outcome, and support the use of novel agents to achieve maximal response in elderly patients, including those more than 75 years. This trial was registered at www.clinicaltrials.gov as #NCT00232934, #ISRCTN 90692740, and #NCT01063179.

Successful treatment of immunoglobulin D myeloma by bortezomib and dexamethasone therapy

Immunoglobulin D (IgD) myeloma is a rare subtype and it is widely accepted as an aggressive disease. Here, we report a 66-year-old woman with IgD myeloma who had anemia, lumbago, multiple osteolytic lesions and hypercalcemia. The patient refused a blood transfusion because of her beliefs, so we administered bortezomib and dexamethasone (BD) after high-dose dexamethasone therapy. Marked improvement of anemia and elevated serum alkaline phosphatase levels was recognized. After 5 cycles of BD therapy, the patient achieved a stringent complete response according to International Myeloma Working Group Response Criteria. BD therapy might be a feasible and useful treatment option for IgD myeloma.

Unique Pattern of Overexpression of Raf-1 Kinase Inhibitory Protein in Its Inactivated Phosphorylated Form in Human Multiple Myeloma

Multiple myeloma (MM) is the second most common hematological and incurable malignancy of plasma cells with low proliferative activity in the bone marrow. MM patients initially respond to conventional therapy, however, many develop resistance and recurrences occur. We have identified RKIP as a novel gene product that is differentially overexpressed in MM cell lines and MM tissues compared to other studied tumors and normal bone marrow. This overexpression consisted, in large part, of a phosphorylated inactive form of RKIP at Ser153 (p-Ser153 RKIP). In contrast to RKIP, p-Ser153 RKIP lacks its ability to inhibit the MAPK signaling pathway. The overexpression of p-Ser153 RKIP in MM cell lines and MM tissues was further validated in a mouse model carrying a human MM xenograft, namely, LAGλ-1B. Bioinformatic analyses from databases support the presence of increased RKIP mRNA expression in MM compared to normal plasma cells. In these databases, high RKIP levels in MM are also correlated with the nonhyperdiploid status and the presence of IgH translocations, parameters that generally display more aggressive clinical features and shorter patients' survival irrespective of the treatment. Since RKIP expression regulates both the NF-κB and MAPK survival pathways, the overexpression of "inactive" p-Ser153 RKIP in MM might contribute positively to the overall cell survival/antiapoptotic phenotype and drug resistance of MM through the constitutive activation of survival pathways and downstream the transcription of anti-apoptotic gene products. The overexpression of RKIP and p-Ser153 RKIP in MM is the first demonstration in the literature, since in most tumor tissues the expression of RKIP is very low and the expression of p-Ser153 RKIP is much lower. The relationship between the levels of active RKIP and inactive p-Ser153 RKIP in MM may be of prognostic significance, and the regulation of RKIP activity may be a target for therapeutic intervention.

Many multiple myelomas: making more of the molecular mayhem

Multiple myeloma (MM) is malignancy of isotype-switched, BM-localized plasma cells that frequently results in bone destruction, BM failure, and death. Important molecular subgroups are identified by three classes of recurrent immunoglobulin gene translocations and hyperdiploidy, both of which affect disease course. From a clinical standpoint, it is critical to identify MM patients carrying the t(4;14) translocation, which is present in 15% of myelomas and is associated with dysregulation of WHSC1/MMSET and often FGFR3. These patients should all receive bortezomib as part of their initial induction treatment because this has been shown to significantly prolong survival. In contrast, patients with translocations affecting the MAF family of transcription factors, del17p, or gene-expression profiling (GEP)-defined high-risk disease appear to have a worse prognosis that is not dramatically improved by any intervention. These patients should be enrolled in innovative clinical trials. The remaining patients with cyclin D translocations or hyperdiploidy do well with most therapies, and the goal should be to control disease while minimizing toxicity.

Multiple myeloma: 2011 update on diagnosis, risk-stratification, and management

DISEASE OVERVIEW

Multiple myeloma is malignant plasma-cell disorder that accounts for ∼10% of all hematologic malignancies.

DIAGNOSIS

The diagnosis requires (1) 10% or more clonal plasma cells on bone marrow examination or a biopsy-proven plasmacytoma plus (2) evidence of end-organ damage felt to be related to the underlying plasma cell disorder.

RISK STRATIFICATION

Patients with 17p deletion, t(4;14), t(14;16), t(14;20), and karyotypic deletion 13 or hypodiploidy are considered to have high-risk myeloma. All others are considered to have standard-risk disease.

RISK-ADAPTED THERAPY

Standard-risk patients are treated with nonalkylator-based therapy such as lenalidomide plus low-dose dexamethasone (Rd) followed by autologous stem-cell transplantation (ASCT). If patients are tolerating the induction regimen treatment well, an alternative strategy is to continue initial therapy after stem-cell collection, reserving ASCT for first relapse. High-risk patients are treated with a bortezomib-based induction followed by ASCT and then bortezomib-based maintenance. Patients not eligible for ASCT can be treated with Rd for standard risk disease or a bortezomib-based regimen if high-risk features are present. To reduce toxicity, when using bortezomib, the once-weekly dose is preferred; similarly, when using dexamethasone, the low-dose approach (40 mg once a week) is preferred, unless there is a need for rapid disease control.

MANAGEMENT OF REFRACTORY DISEASE

Patients with indolent relapse can be treated first with lenalidomide, bortezomib, or alkylators plus low-dose corticosteroids. Patients with more aggressive relapse often require therapy with a combination of multiple active agents. The most promising new agents in development are pomalidomide and carfilizomib.

A high-risk signature for patients with multiple myeloma established from the molecular classification of human myeloma cell lines

BACKGROUND

Multiple myeloma is a plasma-cell tumor with heterogeneity in molecular abnormalities and treatment response.

DESIGN AND METHODS

We have assessed whether human myeloma cell lines have kept patients' heterogeneity using Affymetrix gene expression profiling of 40 human myeloma cell lines obtained with or without IL6 addition and could provide a signature for stratification of patient risk.

RESULTS

Human myeloma cell lines, especially those derived in the presence of IL6, displayed a heterogeneity that overlaps that of the patients with multiple myeloma. Human myeloma cell lines segregated into 6 groups marked by overexpression of MAF, MMSET, CCND1, FRZB with or without overexpression of cancer testis antigens (CTA). Cell lines of CTA/MAF and MAF groups have a translocation involving C-MAF or MAFB, cell lines of groups CCND1-1 and CCND1-2like have a t(11;14) and cell lines of group MMSET have a t(4;14). The CTA/FRZB group comprises cell lines that had no or no recurrent 14q32 translocation. Expression of 248 genes accounted for human myeloma cell line molecular heterogeneity. Human myeloma cell line heterogeneity genes comprise genes with prognostic value for survival of patients making it possible to build a powerful prognostic score involving a total of 13 genes.

CONCLUSIONS

Human myeloma cell lines derived in the presence of IL6 recapitulate the molecular diversity of multiple myeloma that made it possible to design, using human myeloma cell line heterogeneity genes, a high-risk signature for patients at diagnosis. We propose this classification to be used when addressing the physiopathology of multiple myeloma with human myeloma cell lines.

First-line treatment with zoledronic acid as compared with clodronic acid in multiple myeloma (MRC Myeloma IX): a randomised controlled trial

BACKGROUND

Bisphosphonates reduce the risk of skeletal events in patients with malignant bone disease, and zoledronic acid has shown potential anticancer effects in preclinical and clinical studies. We aimed to establish whether bisphosphonates can affect clinical outcomes in patients with multiple myeloma.

METHODS

Patients of age 18 years or older with newly diagnosed multiple myeloma were enrolled from 120 centres in the UK. Computer-generated randomisation sequence was used to allocate patients equally, via an automated telephone service, to receive 4 mg zoledronic acid as an infusion every 3-4 weeks or 1600 mg oral clodronic acid daily. Patients also received intensive or non-intensive induction chemotherapy. No investigators, staff, or patients were masked to treatment allocation, and bisphosphonate and maintenance therapy continued at least until disease progression. The primary endpoints were overall survival, progression-free survival, and overall response rate. We assessed between-group differences with Cox proportional hazards models for progression-free survival and overall survival, and with logistic regression models for overall response rate. Analysis was by intention to treat. This trial is registered, number ISRCTN68454111.

FINDINGS

1970 patients were enrolled between May, 2003, and November, 2007, of whom 1960 were eligible for intention-to-treat analysis: 981 in the zoledronic acid group (555 on intensive chemotherapy, 426 on non-intensive chemotherapy); and 979 on clodronic acid (556 on intensive chemotherapy, 423 on non-intensive chemotherapy). The treatment cutoff was Oct 5, 2009, with patients receiving bisphosphonates for a median of 350 days (IQR 137-632) before disease progression, with a median of 3·7 years' follow-up (IQR 2·9-4·7). Zoledronic acid reduced mortality by 16% (95% CI 4-26) versus clodronic acid (hazard ratio [HR] 0·84, 95% CI 0·74-0·96; p=0·0118), and extended median overall survival by 5·5 months (50·0 months, IQR 21·0 to not reached vs 44·5 months, IQR 16·5 to not reached; p=0·04). Zoledronic acid also significantly improved progression-free survival by 12% (95% CI 2-20) versus clodronic acid (HR 0·88, 95% CI 0·80-0·98; p=0·0179), and increased median progression-free survival by 2·0 months (19·5 months, IQR 9·0-38·0 vs 17·5 months, IQR 8·5-34·0; p=0·07). Rates of complete, very good partial, or partial response did not differ significantly between the zoledronic acid and clodronic acid groups for patients receiving intensive induction chemotherapy (432 patients [78%] vs 422 [76%]; p=0·43) or non-intensive induction chemotherapy (215 [50%] vs 195 [46%]; p=0·18). Both bisphosphonates were generally well tolerated, with similar occurrence of acute renal failure and treatment-emergent serious adverse events, but zoledronic acid was associated with higher rates of confirmed osteonecrosis of the jaw (35 [4%]) than was clodronic acid (3 [<1%]).

INTERPRETATION

Consistent with the potential anticancer activity of zoledronic acid, overall survival improved independently of prevention of skeletal-related events, showing that zoledronic acid has treatment benefits beyond bone health. These findings support immediate treatment with zoledronic acid in patients with newly diagnosed multiple myeloma, not only for prevention of skeletal-related events, but also for potential antimyeloma benefits.

FUNDING

Medical Research Council (London, UK), with unrestricted educational grants from Novartis, Schering Health Care, Chugai, Pharmion, Celgene, and Ortho Biotech.

Chromosomal aberrations +1q21 and del(17p13) predict survival in patients with recurrent multiple myeloma treated with lenalidomide and dexamethasone

BACKGROUND

In the era of novel agents such as lenalidomide and bortezomib, risk stratification by chromosomal abnormalities may enable a more rational selection of therapeutic approaches in patients with multiple myeloma (MM).

METHODS

The authors analyzed the prognostic value of deletion del(13q14), del(17p13), +1q21, translocation t(4;14), t(11;14), and t(14;16) by fluorescence in situ hybridization (FISH) in a series of 92 patients with recurrent MM who were treated with lenalidomide and dexamethasone (len/dex) at the study center.

RESULTS

Patients carrying del(13q14) or t(14;16) were found to have a shorter median time to disease progression (TTP) of 5.1 months (vs 14.4 months; P = .009) and 2.0 months (vs 10.5 months; P <.001), respectively. However, no effect on TTP was observed in patients harboring del(13q14) as an exclusive chromosomal aberration without the concomitant presence of t(4;14) or del(17p13). The median overall survival (OS) for patients with del(17p13) or +1q21 was 6.7 months (P = .002) and 8.3 months (P < .001), respectively, whereas the median OS for patients carrying none of these abnormalities was not reached. Multivariate analysis revealed that the effects of del(17p13) and +1q21 on OS were independent of patient age as well as the type and number of regimens administered before len/dex.

CONCLUSIONS

The results of the current study suggest that the prognostic significance of t(4;14) may be ameliorated or eliminated in patients treated with len/dex, whereas the presence of del(17p13) or +1q21 is still associated with a dismal OS. The presence of t(11;14) and del(13q14) as exclusive chromosomal aberrations indicates no impact on outcome. Because of its rarity in MM, a confirmation of the prognostic role of the t(14;16) aberration is still pending.

Number of expressed cancer/testis antigens identifies focal adhesion pathway genes as possible targets for multiple myeloma therapy

Considering that the importance of cancer/testis (CT) antigens in multiple myeloma (MM) biology is still under investigation, the present study aimed to: (1) identify genes differentially expressed in MM using microarray analysis of plasma cell samples, separated according to the number of expressed CTs; (2) examine possible pathways related to MM pathogenesis; (3) validate the expression of candidate genes by quantitative real-time PCR (RQ-PCR). Three samples predominantly positive (>6 expressed), including the U266 cell line, and three samples predominantly negative (0 or 1 expressed CT for the 13 analyzed CT antigens), were submitted for microarray analysis. Validation by RQ-PCR from 24 MM samples showed that the ITGA5 gene was downregulated in predominantly positive (>6 expressed CTs, p = 0.0030) and in tumor versus normal plasma cells (p = 0.0182). The RhoD gene was overexpressed in tumor plasma cells when compared to normal plasma cells (p = 0.0339). Results of the microarray analysis corroborate the hypothesis that MM could be separated into predominantly positive and predominantly negative expression. The differential expression of ITGA5 and RhoD suggests disruption of the focal adhesion pathway in MM and offers a new target field to be explored in this disease.

Epigenetics and microRNAs combine to modulate the MDM2/p53 axis in myeloma

Avoiding the inhibitory effects of p53 on cell growth is important for tumor progression. In this issue of Cancer Cell, Picchiorri et al. describe epigenetic silencing of MDM2-targeting microRNAs in multiple myeloma (MM), which generally appears to have intact p53 function. This provides the rationale for microRNA-targeted therapy for MM.

RETRACTED: Downregulation of p53-inducible microRNAs 192, 194, and 215 impairs the p53/MDM2 autoregulatory loop in multiple myeloma development

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the editors. This article was published on October 19, 2010, and Figures 4A and 7A were later corrected on August 8, 2016. In January 2021, The Ohio State University notified the Cancer Cell editors that an internal investigation concluded that Figures 1E, 4A, 4D, 5A, and 7A were falsified and that part of Figure 1E of the article is the same as part of Figure 1F in the correction of another article (Pichiorri et al., 2017, J. Exp. Med., 214, 1557, https://doi.org/10.1084/jem.2012095001172017c) and recommended retraction of the article. The editors no longer have confidence in the validity of the data and are retracting the article. S.-S. S. agrees with the retraction, and F.P., C.H., A.P., and C.M.C. disagree with the retraction; all other authors couldn't be reached or didn't respond.

International staging system and metaphase cytogenetic abnormalities in the era of gene expression profiling data in multiple myeloma treated with total therapy 2 and 3 protocols

BACKGROUND

Myeloma survival varies markedly with International Staging System classification, presence of cytogenetic abnormalities, and, especially, gene expression profiling-based risk and delTP53 status, whose collective impact has not been examined in the context of specific therapies.

METHODS

The authors examined overall survival (OS), event-free survival (EFS), and complete response duration (CRD) in Total Therapy 2 with randomization to a control or thalidomide arm and in Total Therapy 3 with added bortezomib. Among 612 patients with complete data sets, multivariate analyses were used to investigate the relative contributions to OS, EFS, and CRD of International Staging System stage, cytogenetic abnormalities, and gene expression profiling-derived risk and delTP53 status, in the context of the 3 Total Therapy regimens.

RESULTS

Whereas gene expression profiling risk segregated outcomes within all 3 International Staging System stages, International Staging System 3 conferred inferior prognosis only in low-risk myeloma, whereas the grave prognosis of high-risk disease was International Staging System-independent. After adjusting for gene expression profiling-defined high risk and delTP53 in multivariate analysis, International Staging System 3 and cytogenetic abnormalities both retained independent adverse implications for OS, EFS, and CRD. Among the 86% with low-risk disease, cytogenetic abnormalities and delTP53 both affected all 3 endpoints negatively, whereas the International Staging System 3 effect was limited to OS. Total Therapy 3 improved survival outcomes beyond results obtained with Total Therapy 2.

CONCLUSIONS

In the genomic era, standard laboratory variables, such as International Staging System stage and presence of cytogenetic abnormalities, continue to impact survival after adjusting for gene expression profiling risk and delTP53 status, providing a basis for stratification in our current practice of gene expression profiling risk-based treatment assignment.

Impact of genomic aberrations including chromosome 1 abnormalities on the outcome of patients with relapsed or refractory multiple myeloma treated with lenalidomide and dexamethasone

Previous literature suggests that cytogenetics may be used for risk-adapted therapy in patients with relapsed/refractory multiple myeloma (MM) treated with lenalidomide and dexamethasone. However, the significance of each abnormality is still unclear, and chromosome 1 abnormalities have yet to be studied in this population. We therefore evaluated genetic risk factors including chromosome 1q gain and 1p loss by cIg-FISH in 143 patients with relapsed/refractory MM treated with lenalidomide and dexamethasone, and correlated the genomic aberrations with patient clinical outcomes. Patients had a median of two (range 1-7) previous therapies in this cohort. A total of 119 out of 143 (83%) patients had an objective response, with median time to progression (TTP) and overall survival (OS) of 11 and 28 months, respectively. Patients with del(1p21) or del(17p) (p53) deletions had a significantly shorter TTP. OS was shorter in patients with 1p21 or 17p deletions, but did not reach statistical significance. Prior bortezomib or thalidomide treatment was associated with shorter TTP and OS. Multivariate analysis identified del(17p), del(1p21), and prior bortezomib or thalidomide therapy as independent risk factors for shorter TTP. Our data suggest that chromosome 17p and 1p21 deletions adversely impact the outcome of lenalidomide and dexamethasone treated patients with relapsed/refractory MM. Improved therapeutic strategies are required for these patients.

An abnormal nonhyperdiploid karyotype is a significant adverse prognostic factor for multiple myeloma in the bortezomib era

Multiple myeloma is clinically heterogeneous and risk stratification is vital for prognostication and informing treatment decisions. As bortezomib is able to overcome several high-risk features of myeloma, the validity of conventional risk-stratification and prognostication systems needs to be reevaluated. We study the survival data of 261 previously untreated myeloma patients managed at our institution, where bortezomib became available from 2004 for the treatment of relapse disease. Patient and disease characteristics, and survival data were evaluated overall, and with respect to bortezomib exposure. Overall, the international staging system (ISS), metaphase karyotyping and interphase fluorescence in situ hybridization (FISH) were discerning of survival outcomes, where the median for the entire cohort was 5.2 years. However, when stratified by bortezomib exposure, only metaphase karyotyping was still discriminating of long-term prognosis. The presence of an abnormal nonhyperdiploid karyotype overrides all other clinical and laboratory parameters in predicting for a worse outcome on multivariate analysis (median survival 2.6 years, P = 0.001), suggesting that bortezomib used at relapse is better able to overcome adverse risk related to high tumor burden (as measured by the ISS) than adverse cytogenetics on conventional karyotyping. Metaphase karyotyping provides additional prognostic information on tumor kinetics where the presence of a normal diploid karyotype in the absence of any high-risk FISH markers correlated with superior survival and could act as a surrogate for lower plasma cell proliferation.

[Molecular pathology of plasma cell neoplasms]

Plasma cell myeloma (PCM) and related immunosecretory disorders are a group of B-cell proliferations with a wide clinical and prognostic spectrum, characterized by the production of monoclonal immunoglobulin by immortalized plasma cells. Recent years have seen an explosion in knowledge on the genetic basis and biology of these diseases, followed by improved clinical risk stratification and the introduction of novel therapeutic concepts, such as treatment with proteasome inhibitors or immunomodulatory substances. PCM is a common malignancy, accounting for approximately 10% of all hematological neoplasms. There is good evidence to support a multistep transformation process in plasma cell neoplasms, which corresponds to clinically discernible disease stages. Monoclonal gammopathy of unknown significance is a common asymptomatic precursor lesion for PCM which carries an approximately 1% annual risk for progression. Terminal disease stages are characterized by increasing genetic complexity and independence from bone marrow stromal cells and show a rapidly increasing tumour load with severe clinical symptoms. Modern diagnostics of plasma cell neoplasms require inclusion of clinical, morphological, immunophenotypical and cytogenetic features to allow for individual risk assessment and therapy planning.

CKS1B nuclear expression is inversely correlated with p27Kip1 expression and is predictive of an adverse survival in patients with multiple myeloma

BACKGROUND

CKS1B is a member of the highly conserved cyclin kinase subunit 1 (CKS1) family that interacts with cyclin-dependent kinases and plays an important role in cell cycle progression. We and others have shown that CKS1B amplification located on chromosome 1q21 is an adverse prognostic factor in multiple myeloma, but its relationship with CKS1B nuclear protein expression, is unclear. The aim of this study was to correlate nuclear CKS1B protein immunoreactivity, 1q21 amplification status, p27(Kip1) expression and survival in patients with newly-diagnosed multiple myeloma.

DESIGN AND METHODS

Nuclear expression of CKS1B and p27(Kip1) was evaluated by immunohistochemistry in decalcified, paraffin-embedded bone marrow biopsies from 94 patients with newly diagnosed multiple myeloma. Clonal plasma cells of the bone marrow aspirates from the same cohort were examined for CKS1B gene status by interphase cytoplasmic fluorescence in situ hybridization.

RESULTS

Fluorescence in situ hybridization detected the 1q21 amplification in 36 (38%) of the 94 patients and immunohistochemistry showed CKS1B protein expression in 37 (39%). Thirty-two (86%) of the 36 amplified (1q21) cases expressed CKS1B and 31 (84%) of the 37 CKS1B immunore-active cases had amplified 1q21. 1q21 amplification and CKS1B protein expression were strongly correlated (P<0.0001). CKS1B protein expression was inversely correlated with p27(Kip1) immunostaining (P<0.0001) and was associated with a shorter overall survival (median 44.5 versus 89.3 months, P<0.0001).

CONCLUSIONS

Immunohistochemistry for CKS1B is a simple, rapid method that appears to predict 1q21 amplification and adverse outcome for risk stratification of patients with multiple myeloma.

The basis and rational use of molecular genetic testing in mature B-cell lymphomas

An increasing number of neoplasms are associated with variably specific genetic abnormalities. This is best exemplified by hematological malignancies, in which there is a growing list of entities that are defined by their genetic lesion(s); this is not (yet) the case in mature B-cell lymphomas. However, enhanced insights into the pathogenesis of this large and diverse group of lymphomas have emerged with the ongoing unraveling of a plethora of fascinating genetic abnormalities. The purpose of this review is to synthesize well-recognized data and nascent discoveries in our understanding of the genetic basis of a spectrum of mature B-cell lymphomas, and how this may be applied to contemporary clinical practice. Despite the explosion of new and exciting knowledge in this arena, with the potential for enhanced diagnostic and prognostic strategies, it is essential to remain cognizant of the limitations (and complexity) of genetic investigations, so that assays can be developed and used both judiciously and rationally.

DNA methylation analysis determines the high frequency of genic hypomethylation and low frequency of hypermethylation events in plasma cell tumors

Multiple myeloma (MM) is a plasma cell malignancy of the bone marrow, which evolves from a premalignant stage called monoclonal gammopathy of undetermined significance (MGUS). In some patients, an intermediate stage referred to as smoldering multiple myeloma (SMM) is clinically recognized, with the full-bore malignancy termed MM. We conducted a study to assess differential CpG methylation at 1,500 genic loci during MM progression and profiled CD138(+) plasma cells from MGUS, SMM, and MM specimens; human myeloma cell lines; and normal plasma cell (NPC) samples. We showed that the number of differentially methylated loci (DML) increased with tumor grade, and the vast majority were due to hypomethylation. Hierarchical clustering analysis revealed samples that coclustered tightly with NPC. These cases, referred to as "normal-like," contained significantly fewer DML when compared with their non-normal-like counterparts and displayed overall methylation levels resembling NPC. This study represents one of the first methylome interrogation studies in MM and points toward global hypomethylation at genic CpG loci as an important and early mechanism driving myelomagenesis. Determining the set of critical genes and pathways based on the myeloma methylome is expected to lead to an improved understanding of biological mechanisms involved in myelomagenesis.

Immunoglobulin D multiple myeloma: response to therapy, survival, and prognostic factors in 75 patients

BACKGROUND

To analyze the clinical features, outcomes including efficacy of treatment, and prognostic factors of patients with immunoglobulin D multiple myeloma (IgD MM).

DESIGN AND METHODS

Seventy-five patients diagnosed with IgD MM were selected from the Korean Myeloma Registry database (www.myeloma.or.kr).

RESULTS

Median age was 57 years and the main presenting features were bone pain (77%). Renal function impairment and hypercalcemia were present in 40 (53%) and 20 (27%) patients. Sixty-seven patients (89%) had lambda light chains. Forty-eight patients (64%) were of stage III by International Staging System. Twenty-six patients (53%) had chromosomal abnormalities mostly by conventional cytogenetics. Thirty-nine patients (54%) were treated with vincristine, adriamycin, and dexamethasone chemotherapy; the overall response rate (ORR) of 56%. Sixteen patients (22%) received first-line chemotherapy including new drugs (bortezomib or thalidomide), with an ORR of 81%. At a median follow-up time of 28.6 months, median overall survival (OS) was 18.5 months. Age, extramedullary plasmacytoma, del(13) or hypoploidy, serum β(2) microglobulin level, and platelet count were significant prognostic factors for OS.

CONCLUSIONS

IgD MM is an aggressive disease that is usually detected at an advanced stage. Despite a positive initial response, survival after relapse was dismal. Intensive treatment strategies before and following stem cell transplantation may improve outcomes in younger patients.

Genetic and molecular mechanisms in multiple myeloma: a route to better understand disease pathogenesis and heterogeneity

Multiple myeloma (MM) is a heterogeneous plasma cell neoplasm presenting with a wide range of clinical manifestations. In spite of the availability of very performing treatment modalities, survival is highly varying, ranging from a few months to several years. Underlying genetic and microenvironmental mechanisms are thought to be responsible for clinical heterogeneity. Disease etiology is unknown but progresses in the understanding of its pathogenesis have shown that MM precursor cell transformation into a malignant one occurs in a multistep process. Possibly during class switch recombination a primary genetic event takes place. With the occurrence of additional events and the support of bone marrow microenvironmental cells, neoplastic plasma cells actively proliferate and disease behavior may change. Recurrent translocations involving the IgH locus (11q13, 4p16, 16q23, 21q12, and 6p21), deletions of chromosome 13, trisomies of chromosomes 3, 5, 9, 11, 15, 19, and 21, and dysregulated expression of cyclin D genes, are considered initiating or primary events. Alterations related to further disease transformation and adverse prognosis are deletion of 17p13, c-myc translocations, and gains of chromosome 1q21. In relation to the underlying genetic defects, disease subgroups are recognized. Accordingly treatment effectiveness may differ among groups. Intense research is ongoing in this field.

Anaplastic plasmacytoma of mouse--establishing parallels between subtypes of mouse and human plasma cell neoplasia

Mouse models may provide an important tool for basic and applied research on human diseases. An ideal tumour model should replicate the phenotypic and molecular characteristics of human malignancy as well as the typical physiological effects and dissemination patterns. The histopathological and molecular genetic characterization of anaplastic plasmacytoma (APCT) in strain NSF.V(+) mice provides an example to achieve this goal for a specific lymphoma subtype. Firstly, it demonstrates that, like plasma-cell neoplasms in humans, those in mice occur as distinct subtypes. Secondly, it shows that mouse APCT exhibits striking parallels to possible human tumour counterparts for which good mouse models of de novo tumour development are sorely needed: IgM(+) multiple myeloma and Waldenström's macroglobulinaemia. Thirdly, it strongly suggests that insertional somatic mutagenesis, by either a murine leukaemia virus or an oncogenic transposon, would be an effective experimental approach to accelerating malignant transformation of mature B cells and plasma cells in mice and, thereby, tagging and uncovering cancer driver genes that may be of great relevance for the tumour initiation and progression in lymphoma.

Presentation and risk stratification--improving prognosis for patients with multiple myeloma

Major improvement milestones in the treatment of patients with multiple myeloma (MM) include the introduction of the melphalan/prednisone combination in the 1960s; high-dose chemotherapy supported by autologous stem cell transplant in the 1980s; and the more recent introduction of the novel agents, thalidomide, lenalidomide, bortezomib, and pegylated liposomal doxorubicin. While, historically, age and eligibility for autologous stem cell transplantation were the primary basis for treatment selection, cytogenetics and other risk stratification methods are increasingly being used to guide treatment, especially with the newer agents. This trend reflects our improved understanding of the numerous genetic and biological abnormalities that mark this complex disease. In the absence of prospective, randomised studies assessing the value of risk stratification in guiding treatment decisions, and the use of the newest therapies, results of a number of studies provide a rationale for this approach. Currently available data indicate that the use of novel therapies in both the induction and maintenance settings, accompanied by risk stratification, may improve prognosis for patients with MM. Large, prospective randomised studies are needed to confirm these early pilot studies.

Identification of translocation products but not K-RAS mutations in memory B cells from patients with multiple myeloma

BACKGROUND

Several laboratories have shown that cells with a memory B-cell phenotype can have the same clonotype as multiple myeloma tumor cells.

DESIGN AND METHODS

The aim of this study was to determine whether some memory B cells have the same genetic alterations as their corresponding multiple myeloma malignant plasma cells. The methodology included sorting multiple myeloma or memory B cells into RNA stabilizing medium for generation of subset-specific polymerase chain reaction complementary DNA libraries from one or 100 cells.

RESULTS

Cells with the phenotype of tumor plasma cells (CD38(++)CD19(-)CD45(-/+)CD56(-/+/++)) or memory B cells (CD38(-)/CD19(+)/CD27(+)) were isolated by flow activated cell sorting. In samples from all four patients with multiple myeloma and from two of the three with monoclonal gammopathy of undetermined significance, we identified memory B cells expressing multiple myeloma-specific oncogenes (FGFR3; IGH-MMSET; CCND1 high) dysregulated by an IGH translocation in the respective tumor plasma cells. By contrast, in seven patients with multiple myeloma, each of whom had tumor plasma cells with a K-RAS61 mutation, a total of 32,400 memory B cells were analyzed using a sensitive allele-specific, competitive blocker polymerase chain reaction assay, but no K-RAS mutations were identified.

CONCLUSIONS

The increased expression of a specific "early" oncogene of multiple myeloma (monoclonal gammopathy of undetermined significance) in some memory B cells suggests that dysregulation of the oncogene occurs in a precursor B-cell that can generate memory B cells and transformed plasma cells. However, if memory B cells lack "late" oncogene (K-RAS) mutations but express the "early" oncogene, they cannot be involved in maintaining the multiple myeloma tumor, but presumably represent a clonotypic remnant that is only partially transformed.

Systemic joint laxity and mandibular range of movement

Primary plasma cell leukemia (pPCL) is a rare and aggressive form of multiple myeloma (MM) that is characterized by the presence of ≥20% circulating plasma cells. Overall survival remains poor despite advances of anti-MM therapy. The disease biology as well as molecular mechanisms that distinguish pPCL from non-pPCL MM remain poorly understood and, given the rarity of the disease, are challenging to study. In an attempt to identify key biological mechanisms that result in the aggressive pPCL phenotype, we performed whole-exome sequencing and gene expression analysis in 23 and 41 patients with newly diagnosed pPCL, respectively. The results reveal an enrichment of complex structural changes and high-risk mutational patterns in pPCL that explain, at least in part, the aggressive nature of the disease. In particular, pPCL patients with traditional low-risk features such as translocation t(11;14) or hyperdiploidy accumulated adverse risk genetic events that could account for the poor outcome in this group. Furthermore, gene expression profiling showed upregulation of adverse risk modifiers in pPCL compared to non-pPCL MM, while adhesion molecules and extracellular matrix proteins became increasingly downregulated. In conclusion, this is one of the largest studies to dissect pPCL on a genomic and molecular level.